Roll density control for slitter winders



H. W. MOSER Nov. 21, 1961 ROLL DENSITY CONTROL FOR SLITTER WINDERS Filed Oct. 31, 1958 2 Sheets-Sheet 2 FIELS.

.HWW 7 4 3,009,666 Patented Nov. 21, 1961 fine 3,009,666 RULE. DENSITY CONTROL FOR SLZLTTER WHNDERS Henry William Moser, Haddonfield, N.J., assignor to Samuel M. Langston Company, Camden, N.J., a corporation of New Jersey Filed st. 31, 1958, Ser. No. 770356 8 Claims. (Cl. 242-66) This invention relates to an automatic torque wrap control for a web winder of the three-roll type, such as shown in the Langston et al. Patent 1,488,126, and the Seig Patents 1,827,862, 1,831,201 and 1,888,810. The usual function of a web winder of the three-roll type is to cut or slit the web of a parent or mill roll into various widths and/or to trim the edges, and to then rewind the cut web into rolls which will have the desired density or tension in the convolutions.

The web is rewound on a winding mandrel which is initially placed between two closely spaced parallel winding drums which support the web roll while it is being rewound. The first or front winding drum usually has the incoming web wound partly around it for traction, due to the fact that it provides most of the driving torque for accelerating the web roll up to rewinding speed, for overcoming the resistance of the operation being performed, such as slitting and trimming, and for overcoming the tension in the sheet provided by drag brakes on the spindles of the unwind stand which support the parent or mill roll during the rewinding process. The second or rear winding drum normally assists the front winding drum in performing its function.

The winding mandrel rests in the valley between these rotating winding drums, and a third roll rests on the top of this winding mandrel and subsequently on the roll being rewound, to exert a downward force during the rewinding. This third roll, called a pressure or rider roll, moves upwardly as the Web roll increases in diameter during the rewinding. The pressure roll may or may not be driven to assist the two winding drums. It i usually motor driven in the larger size rewinders.

A good rewound web roll is one which has certain density characteristic; that is, tension in the convolutions or sheet layers of the roll.

The three factors which influence tension in the convolutions of the Web roll as it is being rewound are as follows:

(1) Winding tension or back tension on the paper or other web entering the rewinder-usually provided by the drag brakes on the spindles of the parent roll unwind stand;

(2) The force exerted on the web roll by the pressure roll;

(3) The torque diiferential between that contributed by the first winding drum and that contributed by the second winding drum and the pressure roll.

This present invention relates to the third of said factors. It contemplates means for manually or automati cally controlling the torque differential between the first winding drum and the combination of the second winding drum and the pressure roll during rewinding. By applying more or less torque at the second contact nip. i.e. where the rewind roll contacts the second winding drum, and the third contact nip, where the pressure roll contacts the rewind roll, the web will be rewound tighter or looser.

A uniform or desired degree of hardness or density throughout the web roll can in this way be maintained, regardless of the fact that the diameter and Weight of the web roll increases as it is being rewound, if these torques are constantly properly regulated during rewinding.

With the control mean of the present invention described below, the machine operator has available to him, by simple manual and automatic control, the means to adjust the torque differential or driving eifort at any time and for any required degree of sheet tensioning. The ability of the second winding drum and pressure roll to induce a tension in the sheet layers of the web roll; to run at paper speed, inducing no tension; and to run with a retarding effort (braking) so as to relieve sheet tension; enables the machine operator by use of the present invention to produce a rewound roll to any density requirement.

The portions of a slitting and rewinding machine essential to an understanding of the present invention are illustrated in the attached drawings, wherein:

FIG. 1 is a side elevational view of the machine;

FIG. 2 is a front elevational view of the machine;

FIG. 3 is a view in perspective of the manual control unit or console;

FIG. 4 is a fragmentary sectional view of a valve element of the hydraulic operating system and its actuating cam, and

FIG. 5 is a diagrammatic View of the hydraulic system and the associated electrical controls.

In this machine, which is hydraulically operated and electrically controlled, the two winding drum 11 and 12, respectively, and the pressure roll 13 are directly connected to and are driven by individual hydraulic motors, indicated respectively by reference numerals 14, 15, and 16, which are powered from four hydraulic pumps, 17, 18, 19, and 21 (see FIG. 5), through a hydraulic fluid system hereinafter described.

The pumps, which are of fixed displacement type, feed from a common sump or reservoir 22 through filters 23 and 24 and are driven by a single A.C. electric motor 25. The pumps supply power to the individual hydraulic constant displacement motors through suitable piping, and the motor speeds and contributing torques are regulated and controlled by various valves and devices. The functions of these valves and devices and the circuitry of the electric and fluid system are described below.

The web 26 drawn from the mill roll enters the machine from the right as viewed in FIG. 1, and passes first through the slitting devices indicated generally at 27. The divided web is then acted on by a spreader 28 from which it passes to the first or rear winding drum 11. In the present instance the web passes to the underside of this drum and upwardly around the far side to the rewind roll 29 which is supported on the drums during winding, and is wound on the mandrel 31 as previously set forth. The opposite ends of the mandrel are journaled in arms 32 pivotally attached to carriages 33 guided on vertical rails 34 on the side frames 35 of the machine.

The second or front drum 12 is supported in journals 36 which are adjustable on the frames 35 in guides 37. By adjusting the journals in the guides the horizontal space between the drums 11 and 12 can be varied. The journals are connected through arms '38 with upright levers 39 pivoted at 41 to the side frames. The upper ends of the levers are connected to trunions of pressure roll 13 by arms 42. The trunions of this roll are held in carriages 43 which are guided on the rails 34 of the side frames. The trunnions also carry gears 44 which mesh with racks 45 on the side frames so that the roll is constrained to move vertically in horizontal position under the displacing effect of the rewind roll as the latter increases in diameter. This movement of the roll is transmitted through arms 42 and 38 and levers 39 to the journals 36 of drum 12, so that the space between the drums 11 and 12 increases with the diameter of the rewind roll. The arms 42 are connected to the plungers 46 of fiuid pressure cylinders 47 pivotally attached to the frames 35, said cylinders affording means for regulating the pressure of the roll 13 on the rewind roll as well as a means for elevating and lowering the roll 13 as required.

One of the carriages 43 has attached thereto a sprocket chain 48 which extends upwardly and over a sprocket 49 on a shaft 51 journaled on the top of one of side frames 35. The depending free end of the chain is weighted as indicated at 52. The shaft 51 carries a cam 53 which engages a follower roller 54 on the stem 55 of a valve 56 on the side frame. The function of this valve will be described below.

Motors 14, and 16 are sized to afford the same surface speed to the two winding drums and to the pressure roll. In accordance with the invention, the first winding drum drive motor 14 is capable of delivering the maximum torque required to operate the rewinder. The second winding drum drive motor 15 is capable of delivering 60% of such maximum torque. The pressure or rider roll drive motor 16 is capable of delivering 12% of the said maximum full torque. The manner in which these motors are controlled to afford the desired results can be best described by reference to FIGS. 3, 4 and 5.

The primary control elements are centered in a console 57 shown in FIG. 3. These elements include start and stop buttons 53 and 59, auto-manual control valve 61, manual torque control valve 62, speed control valve 63, speed indicating gauge 64, and torque Wrap gauge 65. In starting the machine, pressure on start button 58 energizes the solenoid 66 of a four way solenoid operated valve 67, see FIG. 5. Fluid then flows to motors 14, 15 and 16 from pumps 17, 18 and 19, 21, starting the motors. Motor 14 discharges to pilot controlled relief valve 68 which has been preset to control emergency braking of motor 14. Valve 68 is vented through valve 67. Motors 15 and 16 (in parallel) discharge to pilot controlled relief valve 69 which has been pre-set to control emergency braking of motors 15 and 16. Valve 69 is vented through its remote control relief valve 71 and through valve 67. By thus venting valves 68 and 69 through valve 67, valves 65 and 69 are opened wide to their respective drains, allowing unrestricted discharge flow from motors 14, 15 and 16 except in the ease of motors 15 and 16 to overcome back pressure from valve 71. After starting, speed and acceleration of the motors 14, 15 and 16 is regulated by manipulation of speed control valve 63. As valve 63 is turned to the desired speed setting on gauge 64, the pressure in its pilot line is lowered. This causes servo-valve 72 to adjust its opening to allow less fluid, from the pressure line to motor 14, to bypass through to its drain and thus brings that motor up to the speed setting of the valve. Valve 63, by regulation of the servo-valve as described, constitutes a means for starting, jogging, running and stopping the drum 11 and for otherwise operating the drum in the process of threading the machine. Since the motor 14 of drum 11 contributes most of the winding torque, control if its speed will also control the speed of the motors 15 and 16, inasmuch as those motors do not normally possess the power to turn the rewinder and web rolls by themselves, and will therefore be forced to operate at the same speed as motor 14. A pump 73 is directly connected to motor 14 and is hydraulically connected to servo-valve 72 so as to adjust the latter to maintain the speed of the motor 14 and of the drum 11 at the rate set by the speed regulating valve 63. Constant flow regulator 74 maintains a fixed amount of fluid in the speed regulating and control pilot circuit A pilot controlled relief valve 75 vents through its remote control relief valve 76, but when the solenoid 66 is energized, as in starting, the pilot line of valve 75 is closed to the drain by valve 67. The valve 75 then be comes a highpressure relief valve with its internal drain, opening only when the pre-set high pressure is reached. The valve 75 controls the maximum starting torque of motor 14 and is pre-set to afford the desired maximum rate of acceleration of the said motor.

Pilot controlled relief valve 77 bears a similar functional relation to motors 15 and 16. Valve '77 vents through its remote-control relief valve 78 and then through manual torque control valve 62 or automatic torque control valve 56. Valve 56 is actuated by cam 53 as previously set forth, and its function is described below. Valves 62 and 56 thus exercise control manually and automatically, respectively, of the torque contributed by motors 15 and 16.

A low pressure setting of relief valve 75 will cause motor 14 to accelerate the rewinder at a low rate, since the valve in such setting will not permit a high build-up of pressure to the motor and the starting torque will be low. A high pressure setting of the valve 75 will cause the rewinder to accelerate at a relatively high rate, since the valve in such setting will permit a higher buildup of pressure to the motor 14 and the starting torque will be correspondingly high.

For emergency stopping the solenoid 66 of valve 67 is de-energized by pressing stop button 59 on the con sole. Valve 67 is then adjusted to block the venting to its drain of relief valves 63 and 69. These valves then become high-pressure relief valves and open to their respective drains only when the pressure reaches the maximum to which they have been pre-set. Flow of fluid from pumps 17-18 and 1921 is then bypassed through pilot controlled relief valves 75 and 77 to their respective drains. These valves are vented through their remote control valves 76 and 78 respectively, and through valve 67 to drain. By so venting valves 75 and 77 through valve 67, the former valves are opened wide to their drains which affords unrestricted discharge therethrough for pumps 17-18 and 1921 as soon as the back pressure from remote control valves 76 and 78 has been exceeded. Back pressure new builds up between the motor 14 and valve 68, and between motors 15 and 16 and valve 69, and produces a braking effect on the motors, and the resulting slow-down is assisted by tension in the web passing to the machine from the parent roll on the un-' Wind stand. If pressure setting in the valves 68 and 69 is high, the motors 14, 15 and 16 will stop quickly, since the aforesaid back pressure will build up quickly until the high-pressure setting is reached. If pressure setting in the valves 68 and 69 is low, the back pressure build-up will be limited, and the motors and their associated drums and rolls will be stopped more slowly.

The machine may be slowed down or stopped, and its speed may be regulated, by valve 63. With solenoid 66 of valve 67 energized, motors 14, 15 and 16 will discharge fluid through valves 68 and 69 as previously set forth, these valves being vented by valves 67 and 71. As valve 63 is gradually opened, the pressure in its pilot line will be reduced, which causes servo-valve 72 to gradually open its line to drain. Motor 14 then slows down or stops, and this will cause the rewinder also to slow down or stop, since motors 15 and 16 cannot contribute between them enough torque to continue to turn the rewinder and web rolls and will slow down and stop in synchronism with motor 14'. If the web should break between drum 11 and the parent roll on the unwind stand, the emergency stop is used. Any power failure will result in an emergency stop.

As speed control valve 63 is opened, the rewinder will accelerate to full rewinding speed at a rate dictated by the setting of valve 75. Any intermediate setting of valve 63 will afi'ord an operation of the machine at the speed setting of that valve.

Apportionment of the total torque input of motors 14, 15 and 16 between those motors to regulate the density of the rewind roll is effected as follows: Pressure in the line to motors 15 and 16 may be varied to regulate the torque contributed by these motors, by controlling the pressure in the bypass line through pilot controlled relief valve 77. Manual torque control valve 62, or automatic torque control valve 56, as the case may be, acts as a venting valve for valve 77, and valve 77 will therefore maintain pressure in the line as dictated by valve 62 or valve 56. A lower pressure adjustment of valve 62, manually, or of valve 56 automatically, will reduce the pressure in the line to motors 15 and 16 and will thereby reduce their contributed torque, and vice versa. If the pressure in the line to motors 15 and 16 is reduced to less than the setting of relief valve 1, which is the remote control relief valve for valve 69, the latter valve will be controlled by valve 71 and the motors 1S and 16 will then have to overcome the pressure set by valve 71 for valve 69. This will produce a drag or braking elfect on the motors which will reduce web tension in the rewind roll. Check valve 79 prevents valve 62 or 56 from influencing the operation of valve 75. Constant flow regulator valve 81 maintains a fixed amount of fluid for the pressure roll drive motor 16 so that the torque for this motor will be a fixed proportion of the total torques of motors 15 and 16. This prevents motor 16 from running away if the pressure roll 13 is lifted from the rewind roll.

Relief valves 76 and 78 in the by-pass lines with valves 75 and 77 maintain a minimum pressure to keep the fluid lines full to the motors and thus prevent cavitation. The pressure setting for relief valve 71 in the discharge line from motors 15 and 16 must therefore be greater than this minimum pressure in order to insure that these motors can produce a reverse torque. The greater the difference between the pressure setting of valve 71 and valve 78, the greater will be the maximum available reverse torque. The relief valve 71 functions to reduce the effective torque in the motors 15 and 16, and for this reason the maximum pressure setting of valve 71 should be no higher than necessary.

Manually controlled four-way valve 61 can be shifted from manual to automatic, and vice versa, to permit controlling the torque contributed by motors 15 and 16 by manual or automatic means. When valve 61 is shifted to manual, as shown in FIG. 5, valve 62 can be used to manually control the torque contributed by the motors 15 and 16 as described. Valve 62 is infinitely adjustable, and can be adjusted at any time to regulate toany desired degree the contributed torque from a maximum of 60% of total input power to a minus resulting in a drag or braking troque. Torque Wrap gauge 64 shows by hydraulic pressure (in p.s.i.) the amount of torque wrap effort being contributed by motors and 16 to the rewind roll.

As indicated above, the system of motor control provides for regulating the torque contributed by motors 15 and 16 between a minus valve through zero to a positive value consistent with the maximum joint torque output of the said motors. In the present instance, gauge 64 is calibrated to read plus 60 to minus 10. The plus 60 reading indicates that the valve adjustment is such that motors 15 and 16 are jointly contributing 60% of the total winding force necessary to operate the machine while the motor 14- is contributing 40%. A plus 20 reading would indicate a 20% contribution on the part of motors 15 and 16, with the motor 14 contributing 80%. At zero reading, the motors 1'5 and 16 will be running at paper speed and contributing no torque, while the motor 14 is expending of driving effort. If the indication on the gauge is a minus value, the motors 15 and 16 will be retarded as previously described, and will have a braking effect, as described above, against the 100% of total operating torque exerted by the motor 14.

When the valve 61 is shifted to automatic, from the manual position in which it is shown in FIG. 5, the valve 62 will be cut out of operation, and valve 56 will be cut into the control circuit. Valve 56 will function in the same manner as valve 62 described above, except that it is controlled by cam 53. The contour of this cam, which makes approximately one revolution during comple-te winding of the roll 29, is such that it increases the torque differential between the motor 14 and the motors 15 and 16 in accordance with a pre-selected gradient calculated to compensate for increasing roll density resulting normally from the increasing diameter and weight of the rewind roll as the winding progresses.

I claim:

1. In a machine for winding a web of material into a roll and of the type comprising first and second winding drums for jointly supporting the roll during winding, and with the first of which drums the web in passing to the said roll has initial tractive contact, separate motors for said first and second drums, the motor driving the first drum exerting suflicient torque to overcome the speed and web tension requirements of said machine, the other of said motors being an adjustable torque motor, the second drum, driven by said adjustable torque motor, having a torque output flow thereof to the adjacent web layer of the winding roll, and means operable for independently positively varying and controlling said torque output flow of said adjustable torque motor with respect to the other of said motors during the entire winding operation to control the web tension in the outermost sheet layer of the roll between the contact points thereof at the first and second drums, for controlling the density of the roll comprised of the web layers, and maintaining a tractive driving force in the outermost web layer of the roll at the contact point of the second drum within the static friction condition between the drum surface and web to prevent slippage between said drum and the material during the complete winding cycle of the roll.

2. In a machine as claimed in claim 1, means for adjusting said torque output flow of said second drum in predetermined relation to the increasing diameter of the winding roll to progressively compensate the normal effect of increasing winding roll Weight on the density of the roll.

3. In a machine as claimed in claim 1, a roll for applying pressure to the web roll, an individual adjustable torque motor for driving said pressure roll, and means operable for independently varying and controlling jointly the torque output how of said second drum and said pressure roll during the entire winding operation to control said web tension in the outermost web layer of the web roll between the contact points at the first drum, pressure roll and second drum for controlling density of the roll comprised of the web layers.

4. In a machine as claimed in claim 3, wherein the joint torque output of the second drum and pressure roll motors is variable between zero and a predetermined maximum.

5. In a machine as claimed in claim 4, wherein the joint torque output of the second drum and pressure roll motors is adjustable to a negative value.

6. In a machine as claimed in claim 3, wherein the said means for varying the torque output of the second drum and pressure roll motors is responsive progressively 1 to the increasing diameter of the webroll.

7. In a machine as claimed in claim 1, and wherein said torque output varying and controlling means are 8 operable to maintain surface speed of said second drum References Cited in the file of this patent such that slippage is prevented between said second drum UNITED STATES PATENTS and the web in contact therewith.

8. In a machine as claimed in claim 1, wherein both gifi i flg' fg k i said motors are adjustable torque motors, and said means 5 1868285 Francis 5 1932 for varying and controlling torque output flow being 7O12118 camera; g 1935 operatively connected to both said motors and independ- 498234 Baker et 1950 ently operable to vary the torque output flow of one said 2:733:018 Nitchie 1956 drum with respect to the other 2,890,000 Beachler June 9, 1959 

